Different colors Favicon

I have Nextcloud three times and I chose a different design for all three clouds. One cloud is red, one wine-red and one pink. With the red cloud, the favicon has always remained blue. In the wine-red cloud the favicon was wine-red until the 19.0.3 update, now it’s blue, in the pink cloud it’s still pink.
I changed the design settings for all clouds in the same way, but only on one of them the favicon is colored. Since I have all three clouds always open side by side, the color difference is helpful.
grafik

usually manual helps in such cases

https://docs.nextcloud.com/server/latest/admin_manual/configuration_server/theming.html#theming-of-icons

so you should check wether you have all setup-messages solved and installed evey dependency needed.